使用if语句检查变量true [英] Check variable true with if statement

问题描述

这是我的代码：

$(val1).mouseleave(function () {
    flag = false;
    $(val3 + "," + val4).mouseenter(function () {

        flag = true;
        //alert(flag);

    });
    if (flag == true) {
        //alert("if"+flag);
        $(".big" + i + j + "boxer").show();
        $(".big" + i + "box").show();
        $(".big" + i + "box").append('<div class="opacity" style="background-color:rgba(00,00,00,0.77);position:absolute;top:0;right:0;left:0;bottom:0;"></div>')
        $(".small" + i + "box").append('<div class="opacity" style="background-color:rgba(00,00,00,0.77);position:absolute;top:0;right:0;left:0;bottom:0;"></div>')

    } else {
        //alert("else"+flag);
        $('.opacity').remove();
        $(val2).hide();
        $(val3).show();

    }
});

它不符合 flag = true 条件。如果我 alert 在 $（val1）.mouseleave（function（）{}）; 中，则显示 flag = true ;但是当我在 $（val1）.mouseleave（function（）{}）; 之外提醒它时，它显示 flag = false 。

It's not meeting flag = true condition. If I alert within $(val1).mouseleave(function(){});, it shows that flag = true; but when I alert it outside of $(val1).mouseleave(function(){});, it shows flag = false.

好吧，让我解释一下：我有4个街区 val1，val2，val3 和 VAL4 。当用户离开 val1 并输入 val3 或 val4 阻止，我想设置/添加不透明度等级 ...如果他们不输入进入 val3 / val4 但进入进入 val2或其他块块然后我想删除不透明度类。

Well, let me explain: I have 4 blocks val1,val2,val3 and val4. When the users leave val1 and enter the val3 or val4 block, I want to set/add opacity class ... if they do not enter into val3/val4 but go into val2 or another block block then I want to remove opacity class.

推荐答案

在您进行if测试时：

if(flag==true)

... flag 总是为false，因为您在此之前将其设置为 false 。它被设置为 true 的唯一位置是你绑定的 mouseenter 处理程序，但处理程序函数没有在那一点上被调用。

...flag will always be false, because you set it to false just before that. The only place it gets set to true is inside the mouseenter handler that you bind there but that handler function doesn't get called at that point.

让我在代码的开头添加一些注释，试图让它更清晰：

Let me add some comments to the beginning of your code to try to make that clearer:

$(val1).mouseleave(function () {
    flag = false;                                  // set flag to false
    $(val3 + "," + val4).mouseenter(function () {  // bind a mouseenter
        flag = true;                               // that won't be called immediately
        //alert(flag);                             // so won't change flag yet
    });
    if (flag == true) {                            // flag is still false

从 mouseleave 处理程序中绑定 mouseenter 处理程序是没有意义的，因为表示每次发生mouseleave时都绑定一个额外的 mousee nter 相同元素的处理程序。

It doesn't make sense to bind a mouseenter handler from inside the mouseleave handler, because that means every time the mouseleave occurs you bind an additional mouseenter handler to the same elements.

我无法真正建议一个特定的解决方案，因为你还没有解释你想要的效果实现。 （但我可能首先在其他地方移动 mouseenter 代码。）

I can't really suggest a specific solution because you haven't explained what effect you are trying to achieve. (But I'd probably start by moving that mouseenter code somewhere else.)

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